@type t() :: %Paypal.Subscription.Transactions{
  links: [Paypal.Common.Link.t()],
  total_items: integer() | nil,
  total_pages: integer() | nil,
  transactions: [Paypal.Subscription.Transaction.t()]
}

Subscription transactions structure:

• transactions - List of subscription transactions.
• total_items - Total count of items available across pages.
• total_pages - Total number of pages available.
• links - HATEOAS pagination links.